The 15-meter (50-foot) boat sank over the weekend off Turkey's Aegean coast, and most of the bodies were recovered on Monday, said Ercan Dogu, spokesman for the local governor in the coastal city of Izmir.
Dogu said most of the migrants on the boat were Palestinians, Somalis and Iraqis.
The boat left Seferihisar, a town south of Izmir, with 85 people aboard and the vessel capsized in stormy weather about two hours after setting sail, according to local officials.
Six people were rescued, and paramilitary police and the coast guard were still searching for missing migrants with the help of local fishermen.
Thousands of immigrants from Asia and Africa enter Turkey illegally on their way to European Union countries in search of jobs and a better life. Smugglers often take the migrants from the Turkish coast to nearby Greek islands on fragile and overcrowded boats, and accidents are common.
The EU, which Turkey is seeking to join, wants the country to crack down on illegal immigration.
EU member Greece, which has a 13,000-kilometer (8,000-mile) coastline dotted with thousands of islands, has accused Turkish authorities of not doing enough to halt the flow of illegal migrants. Turkey has accused Greece of forcing illegal migrants to return to Turkish waters.
Last month, coast guard officials from Turkey and Greece agreed to improve communication in order to curb the problem.